#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <string.h>
 
int main(int argc, char const *argv[])
{
	// 创建一个共享内存对象ls
	char shm_name[256] = {0};
	sprintf(shm_name, "/letter %d", getpid());
	// 打开共享内存对象
	int fd = shm_open(shm_name, O_RDWR | O_CREAT, 0644);
	if(fd == -1)
	{
		perror("shm_open");
		exit(EXIT_FAILURE);
	}
	while (1)
	{
		/* code */
	}
	
	return 0;
}